Lightning-arrester



E." A. EVERETT.

LIGHTNING ARRESTER.

APPLICATION FILED SEPT. 15. 1920.

1,401,596. QPatented Dec. 27, 1921.

4 Hg. 5 Q 1 P H L/ne l 5 Z], Grou 74 Line Edw 'INVENTOR W y/ I I ""ATTORNEY UNITED STATES PATENT OFFICE.

LIGHTNING-ARBESTER.

Application filed September 15, 1920.

T 0 all whom. it may concern:

Be it known that I, EDWARD ALLEN EVERETT, a citizen of the United States, and a resident of Long Island City, in the county of Queens and State of New York, have invented certain new and useful Improvements in Lightning-Arresters, of which the following is a specification.

This invention relates to lightning arresters such as are used on telegraph lines and has for an object to provide a device of this kind which is simple in construction and cannot get out of order, and which is easily adjusted. These objects are obtained by the construction described in the following specification and shown in the accompanying drawing in which Figure 1 is a side elevation of the arrester in place, Fig. 2 is a plan view looking on the top of the arrester and Figs. 3 and 1, are details.

This arrester is of the spark gap type, having a washer of carborundum or other insulating and non-fusible material connected to the ground terminal and metallic strips with saw teeth surrounding the carhorundum connected to the line wires. The novelty in the presentinvention consists in means for obtaining the spark gap and providing a clearance which does not vary with irregularities in the size of the carborundum.

In the drawings, 1-1 represents the supporting member to which the porcelain base 12 of the arrester is secured by suitable screws 16. 13 and 14 are the line terminals of the arrester to one of which the incoming line is attached and to the other of which the outgoing line is attached. The central terminal 15, connects to ground. This terminal secures in place the carborundum washer 21 and the brass plates 22, Fig. 3, are placed on the terminals 13 and 14, by means of the slotted openings 23 and suitably secured in place by the binding screws. The end of this brass late is curved, as shown to the radius 0 the carborundum washer 21 and provided with saw teeth. In addition two slotted openings 26, are provided in this plate for supporting the mica spacer 24, Fig. 1, which has a corresponding slot 25. The mica is .built up in. layers according to this shape until it fits slot 26 tightly when it is driven home, the slot 26 ripping the sides of the mica and slot 25 of the mica gripping the sides of the brass plate 22. The outer ends of these mica Specification of Letters Patent.

Patented Dec. 27, 1921.

Serial no. 410,523.

spacers, it will be noted, engage the surface of the carboruiulum wheel 21, Fig. 2, and thus insure that the brass strips 22 are spaced exactly at the proper sparking distance tron'i the grounded terminal, which is a matter of the first importance in a device of this kind.

In practice it is not possible to obtain carborundum wheels or washers of the type shown that are exactly of the same diameter nor is it possible to assemble these on the binding post without a certain amount of eccentricity. By the arrangement shown in this invention, the brass strips 22 are moved by means of the slot 23 until the mica spacers 24 bind against the carborundurn 21,

thus insuring a uniform spark gap in a simple and ett'ective manner. The use of two snacers in each strip alines the spacer with the circumference of the carborundum wheel and maintains the brass plates 22 in alinement.

Having thus described my invention, I claim:

1. In a device of the class described, in combination, an incoming line terminal strip with saw teeth, an outgoing linc termi nal strip with saw teeth, a block of carborundum with a ground connection between the saw teeth of said strips, a mica spacer supported by said strips, said spacer regulating the air gap between said strips and said carborundum block.

2. In a deviceof the class described, the combination of an incoming line terminal having an adjustable strip with saw teeth, an outgoing line terminal having an adjustable strip with saw teeth, a grounded block of carborumlum, aplurality of mica spacers supported by slots in said strips, said spacers regulating the air gap between said strips and said carborundum block.

3. In a device of the class described, in combination, an incoming line terminal ineluding a terminal strip with a slotted opening, an outgoing line terminal. also including a,terminal strip with a slotted opening, the ends of said strip provided with saw teeth arranged in an are, a. carborundum wheel placed in the are formed by said terminal strips, a plurality of mica spacers in each strip for regulating the air gap-between said strips and said carborund'um wheel.

4. In a device of the class described, in combination, an incoming line terminal with a terminal stri and an outgoing line termidum Wheel at different p0ints,'to regulate nal with a terminal strip, said strips having the air gap between said .strips and said saw teeth formed in the arc of a circle, a carborundum wheel.

circular wheel of carborundum placed be- Signed at Long Island City in thecounty tween said strips on a grounded terminal, a of Queens and State of New York, this 13th plurality of mica spacers supported by each day of Sept, A. D. 1920. .i .1 strip, said spacers engaging said carborun- ARD ALLENv 

